text: Techniques based on the Kautsky effect do not exhaust the variety of detection and evaluation methods based on the chlorophyll fluorescence.
  In particular, recent advances in the area of laser-induced fluorescence (LIF) also provide an opportunity of developing sufficiently compact and efficient sensors for 
  photophysiological status and biomass assessments. 
  Instead of measuring the evolution of the total fluorescence flux, such sensors record the spectral density of this flux excited by strong monochromatic laser light pulses of nanoseconds duration.
  Requiring no 15- 20 min dark adaptation period (as is the case for the Kautsky effect methods) and being
  capable to excite the sample from considerable distance, the LIF sensors can provide fast and remote evaluation.
  * Application of the LIF technique to the assessment of drought stress in cork oak (Quercus suber) and maritime pine (Pinus pinaster) on the basis of chlorophyll emission ratio I/I is described in Ref. Recently the LIF sensing technique was harnessed to address the role of pPLAIIα protein in the protection of the photosynthetic metabolism during drought stress using genetically modified Arabidopsis plants.
  * In 2011, Vieira et al. applied a compact low-cost LIF sensor (built around a frequency-doubled solid-state Q-switched Nd:YAG laser and a specially modified commercial miniature fiber optic spectrometer Ocean Optics USB4000) to study intertidal microphytobenthos communities. Chlorophyll emission enabled the researchers to adequately assess the surface biomass and track migratory rhythms of epipelic benthic microalgae in muddy sediments.